Fire Protection with High Pressure Water Mist in the Tobacco Warehouse Dr. Cong Beihua Tongji Antai Research Center of Disaster Prevention Engineering, Shanghai Yatai Fire Engineering Co., LTD. 2010.11
Outline Fire Risks in the Tobacco Warehouse Full Scale Fire Tests with High Pressure Water Mist in the Simulated Storage Site Fire Tests in the Tobacco Warehouse Summary
Fire Risks in the Tobacco Warehouse Concentration of large combustible storage with very high fire load Large buildings to protect the unit relatively independent Complicated fire hazards -Spontaneous Combustion -Fumigation fire caused by improper operation - Electrical fire / illegal use of fires - Arson Coexistence of various forms of fires (surface fire, deep-seated fire, flaming fire, smoldering fire etc), easy to form three-dimensional fires, difficult for fire fighting Huge losses caused the improper fire fighting will be much greater than fire losses
Alcoholization Warehouse Tobacco leaf box
High-rack Warehouse Cigarette box
Fire cases July 5, 2008, Arson fire in Hainan Hongta cigarette factory, Fire loss: 0.23 billion
Fire cases December 28, 2008, Spontaneous fire in Yongzhou tobacco warehouse, Fire loss: 0.12 billion
Requirements of fire extinguishing system in the tobacco warehouse Efficient and reliable for early fire extinguishing Continuous fire fighting ability for re-ignition Reduce the losses caused by fire fighting Safe and reliable to avoid losses caused by malfunction Low operating costs, convenience for repair and maintenance Adaption to the tobacco Production technology Environmentally friendly
Application of High Pressure Water Mist System in the Tobacco Warehouse Wetting system Pre-action system Open system Protected Zone
Simulated Fire tests(1) Ceiling closed nozzle K=2.04, RTI<20, P=10MPa,57 C 12.0m 12.0m 5.6m(high),single floor storage
Simulated Fire tests(2) Ceiling closed nozzle K=2.04, RTI<20, P=10MPa,57 C Built-in closed nozzle K=1.25, RTI<20, P=10MPa,57 C 12.0m 12.0m 8.5m(high),high-rack storage
Combustibles tobacco leaf Cigarette
Design fire Scenario(1) nozzle (a)tobacco crib test Max Nozzle space: 3.5m
Design fire Scenario(2) nozzle (b) High-rack storage test Max Nozzle space: 3.0m
Tobacco crib test results Free burning Nozzle activated Fire suppressed Surface fire extinguished Fire fighting with mist gun Total Fire extinguished
Tobacoo crib test results Temperature change during the test
High-rack storage test results(1) Free burning Nozzle activated Fire extinguished After Fires
High-rack storage test results(1) Temperature change during the test
High-rack storage test results(2) Nozzle activated Fire extinguished Fires spreading from the under box
High-rack storage test results(2) 高压细水雾扑灭烟草高架库房火灾 600 500 400 300 200 温度 2 温度 3 温度 4 100 0 11:05:59 11:06:44 11:07:29 11:08:14 11:08:59 11:09:44 11:10:29 11:11:14 11:11:59 11:12:44 11:13:29 11:14:14 11:14:59 11:15:44 11:16:29 11:17:14 11:17:59 11:18:44 温度 时间 Temperature change during the test
Site fire tests in Yunnan Hongta tobacco warehouse 27.0m 36.0m 5.6m(high),single floor storage Totally 12 tobacco cribs, each crib is 7m long, 6m wide and 4m high.
Site fire tests setup 细水雾灭火系统安装示意图 Open nozzle activated by air sample detection system K=0.95, P=10MPa, Max nozzle space 3.0m Ignited crib 喷头安装位置说明 : 根据 12 个防护区划分, 喷头距离墙体中心点 1.5 米, 其余间距 3 米
Site fire test results-surface fires
Site fire test results-deep-seated fires
Site fire tests in Guangdong Shima tobacco warehouse Ceiling closed nozzle K=1.25, RTI<20, P=10MPa,57 C Max nozzle space 3.0m HP water mist pipe 8.0m 7.0m 4.0m( 高 )
Combustibles Cigarettes(200 boxes)
Design fire Scenario Arson fires with gasoline
Site fire test results -Arson fires Ignition Nozzle activated Fire suppressed Flame fire extinguished
Site fire test results -Arson fires Re-ignition Nozzle activated Fire suppressed with mist gun Total fire extinguishment
Summary Fire protection is very important in the tobacco warehouse because of the high value. High pressure water mist system with less water and less water damage is regarded as priority option in the tobacco warehouse. Both simulated and site fire tests showed that high pressure water mist could extinguish surface fires of tobacco crib less than five minitues, while deep seat fires or smolder fires would only be controlled or suppressed. However, the decline of fire temperature was conducive to firefighters quickly approaching and fighting fire. High-pressure water mist gun was proved to a good manual fire fighting way in the tobacco warehouse. Further work was carried on evaluating the risk of water mist on fumigation. Because in the fumigation of tobacco leaf, aluminium phosphide was used as the pesticide. However there was risk of explosion due to the pesticide decomposition products reaction with water.
Thanks! bhcong@tongji.edu.cn